ok got this camera open ok, removed old film that was at least 20 years old, now how do i get film wind knob to re-engage? it does not seem to want to drop back into position.knob is just free wheeling....any further help is appreciated. thanks:)

With mine, simply turning the knob causes it to drop back into normal position and it re-engages. Specifically, when I disengage it, there is spring tension on it. Turning it then about 1/4 turn finds the detent, whereupon the spring tension drops it back into engaged position. Fred.